This section introduces aspects that may be helpful in facilitating a better understanding of embodiments. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is in the prior art or what is not in the prior art.
In the field of automotive engineering it may be required to monitor a wheel speed of wheels of a vehicle or of other rotatable bodies of the vehicle. The wheel speed may be used, for example, in Anti-lock Braking System (ABS) applications or in transmission applications. Usually, wheel speed information is transmitted in a standard output protocol, for example as a current protocol with a low current Ilow=7 mA and a high current Ihigh=14 mA from a sensor to an ECU of the vehicle. It may be useful to further provide the ECU with safety information, for instance about an error event. For this reason, a constant current Ilow=7 mA or Ihigh=14 mA may be output in case of an error event, for example, if an external supply voltage falls below a predetermined low-voltage value or if a bit error appears in an internal sensor storage. Thus, the ECU may recognize the error event. If an internal error occurs and is detected chip internally, this fault has to be signalized with a constant Ilow or a constant Ihigh current-level. In this case it is typically not possible to distinguish, for example, between an error indication or a wheel stands still, signalized by the wheel speed sensor to the ECU.